Celiac disease, also known as coeliac disease or Celiac sprue (Coeliac sprue), affects approximately 1% of people in Europe and North America. In many of those affected, Celiac disease is unrecognised, but this clinical oversight is now being rectified with greater clinical awareness. A gluten free diet is the only currently approved treatment for Celiac disease, and because regular ingestion of as little as 50 mg of gluten (equivalent to 1/100th of a standard slice of bread) can damage the small intestine; chronic inflammation of the small bowel is commonplace in subjects on a gluten free diet. Persistent inflammation of the small intestine has been shown to increase the risk of cancer, osteoporosis and death. As gluten is so widely used, for example, in commercial soups, sauces, ice-creams, etc., maintaining a gluten-free diet is difficult.
Celiac disease occurs in genetically susceptible individuals who possess either HLA-DQ2.5 (encoded by the genes HLA-DQA1*05 and HLA-DQB1*02) accounting for about 90% of individuals, HLA-DQ2.2 (encoded by the genes HLA-DQA1*02 and HLA-DQB1*02), or HLA-DQ8 (encoded by the genes HLA-DQA1*03 and HLA-DQB1*0302). Without wishing to be bound by theory, it is believed that such individuals mount an inappropriate HLA-DQ2- and/or DQ8-restricted CD4+ T cell-mediated immune response to peptides derived from the aqueous-insoluble proteins of wheat flour, gluten, and related proteins in rye and barley.